/*
 * Copyright (c) 2025 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { ConfigSchema, inspectSchema } from "@idlizer/core"

function mergeJSON(a: unknown, b: unknown, path: string[], schema: ConfigSchema<any>): unknown {
    if (a === undefined && b !== undefined) {
        return b
    }
    if (b === undefined && a !== undefined) {
        return a
    }
    const inspector = inspectSchema(schema)
    const info = inspector.inspectPath(path.join('.'))
    if (!info || info.mergeStrategy !== 'replace') {
        if (Array.isArray(a) && Array.isArray(b)) {
            return a.concat(b)
        }
        if (typeof a === 'object' && typeof b === 'object') {
            if (a !== null && b !== null) {
                const aObj = a as any
                const bObj = b as any
                const result: any = {}
                for (const key in a) {
                    if (key in b) {
                        result[key] = mergeJSON(aObj[key], bObj[key], path.concat([key]), schema)
                    } else {
                        result[key] = aObj[key]
                    }
                }
                for (const key in b) {
                    if (key in a) {
                        result[key] = mergeJSON(aObj[key], bObj[key], path.concat([key]), schema)
                    } else {
                        result[key] = bObj[key]
                    }
                }
                return result
            }
        }
    }
    return b
}

export function mergeJSONs(objects: unknown[], schema: ConfigSchema<any>): unknown {
    let result = undefined
    for (const obj of objects) {
        result = mergeJSON(result, obj, [], schema)
    }
    return result
}
